Of course what one gets from an app like this is never enough, but as far as the trig apps go, this is by comparison one of the best. With $1.99 up front there are no in-app purchases. Recommended if you need a quick reference for physics or engineering.

(59 stars)

by Wesley Loveless on 08/05/2014

Thank you !!

(59 stars)

by Bruce M. Pomeroy on 25/08/2013

Excellent

(59 stars)

by Matt J. on 11/04/2013

I bought this, took a quiz and then got distracted for 10 minutes by my son. Now I can't get a refund, but, I would if I could. The questions run off of the screen, the quizzes don't change (same 10 questions)... not impressed.